A gas turbine engine generally includes a compressor section, a combustor or combustor section, and a turbine section. The compressor section receives and compresses a flow of intake air. The compressed air then enters the combustor section in which a steady stream of fuel is injected, mixed with the compressed air, and ignited, resulting in high energy combustion gas, which is then directed to the turbine section. Some gas turbine engines may also include a source for providing a cooling fluid, such as air, within the engine, for example upstream of the turbine section and/or downstream of the compressor section. The cooling fluid may be circulated through the engine and a heat exchanger via a tube or conduit, which may be routed through the combustor.
The combustor generally includes an inner wall and an outer wall defining a combustion chamber there between, where the inner wall and the outer wall have different thicknesses for structural and pressure containment purposes. The compressed air discharged from the compressor section typically is at high temperatures, and therefore heats the combustor walls as it is introduced into the combustor. However, because of the different thicknesses, the inner wall and the outer wall may thermally grow at different rates. This, in turn, may affect or limit the implementation of any structures that interface with the walls, such as a tube or conduit within the combustion chamber that are through which the cooling fluid flows.
As such, there exists a need for a gas turbine engine that accounts for the differential thermal growth between the inner wall and the outer wall of the combustor. In particular, there exists a need for a gas turbine engine implementing a tubular arrangement for providing turbine cooling air such that the tubular arrangement may be provided in the combustion chamber and accommodates the differential thermal growth between the inner wall and the outer wall of the combustor.